My 1999 gmcXXXXXSierra has no brake light or cruise controlI've checked the fuses
Country: United StatesMake: GMCModel: Sierra 1500 Classic SLEYear: 1999Engine: 5.3
I've checked the fuses
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I replaced the switch I forgot to add this to the responce
OK. This sounds like it's going to be some sort of electrical problem. Unfortunately, not my strongest area. I am going to opt-out and forward you to another Tech that may better assist you. Sit tight one sec, someone will be right with you...
Hello and thank you for trusting me with your question. My name is XXXXX XXXXX X will do my best to help you with your GMC problem.New expert here. Do you have a test light or voltmeter to do some power testing on the circuits?
Y I have a voltmeter
Relist: Other.I'm still waiting for an answer (since 7:30 am
Sorry for the delay. Internet problems. Think it is fixed for now.Test for power on the orange wire at the brake switch. If you have power there, test for power on the white (or light blue) wire with the brake pedal depressed. Let me know what you find.
I have power white when the brake is depressed
Double check the VEH STOP and CHMSL fuses in the underhood fuse panel. If the fuses are okay, test for power at each of these fuses with the brake pedal depressed. Then let me know.
Both are good and have power to them (I purchased a test light)
Does the center brake light work, or do you have no brake lights at all?
(No) I have no brake lights at all.
Under the rear of the truck on the drivers side there is a junction for the rear lighting. There you will find a connection for the wiring from the front of the vehicle, both taillights plug in there as well. On the harness from the front of the vehicle, test for power on the light blue wire with the brake pedal depressed. Let me know what you find there.
There is two light blue one had power and the other didn't with the brake depressed
Does power go off when brake pedal is released? Test wire harness coming out of junction to each taillight. Should still be a light blue wire
Yes the power goes off when I release the brake, I get no power coming from the power box at the blue wire
Check the diagram below. If the light blue wire that has power is the same as the one shown in the diagram then your problem is in the junction block. Replacing the junction block should then fix your problem.If you would like any additional information or have more questions please don’t hesitate to ask! Please remember to only rate my answer when you are 100% satisfied. IF you feel the need to rate "Poor Service" or "Bad Service", please stop and reply to me via the REPLY TO EXPERT button with the issue you have. I will be happy to continue further and do everything I can to provide you with the service you seek.I am not paid unless I get a rating of 3 to 5 Stars/Smiley Faces. If I have helped you with your question, please give me an appropriate rating so that I get credit for helping you.Thank you,David
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